CumInCAD is a Cumulative Index about publications in Computer Aided Architectural Design
supported by the sibling associations ACADIA, CAADRIA, eCAADe, SIGraDi, ASCAAD and CAAD futures

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_id 6094
authors Blinn, J.I.
year 1982
title A Generalization of Algebraic Surface Drawing
source ACM Transaction on Graphics, vol. 1, no. 3, pp. 235-256, 1982
summary The technology of creating realistic and visually interesting images of three- dimensional shapes is advancing on many fronts. One such front is the develop- ment of algorithms for drawing curved surfaces directly from their mathematical definitions rather than by dividing them into large numbers of polygons. Two classes of surfaces which have received attention are the quadric and the bivariate parametric surfaces. Bivariate parametric surfaces are generated by three func- tions of two variables (most popularly polynomials), as the variables take on different values. Algorithms dealing with such surfaces are due to Catmull; Lane, Carpenter, Whitted and Blinn; and Clark.
series journal paper
last changed 2003/11/21 14:16

_id 8c27
authors Kalay, Yehuda E.
year 1982
title Determining the Spatial Containment of a Point in General Polyhedra
source Computer graphics and Image Processing. 1982. vol. 19: pp. 303-334 : ill. includes bibliography. See also criticism and improvements in Orlowski, Marian
summary Determining the inclusion of a point in volume-enclosing polyhedra (shapes) in 3D space is, in principle, the extension of the well-known problem of determining the inclusion of a point in a polygon in 2D space. However, the extra degree of freedom makes 3D point-polyhedron containment analysis much more difficult to solve than the 2D point polygon problem, mainly because of the nonsequential ordering of the shape elements, which requires global shape data to be applied for resolving special cases. Two general O(n) algorithms for solving the problem by reducing the 3D case into the solvable 2D case are presented. The first algorithm, denoted 'the projection method,' is applicable to any planar- faced polyhedron, reducing the dimensionality by employing parallel projection to generate planar images of the shape faces, together with an image of the point being tested for inclusion. The containment relationship of these images is used to increment a global parity-counter when appropriate, representing an abstraction for counting the intersections between the surface of the shape and a halfline extending from the point to infinity. An 'inside' relationship is established when the parity-count is odd. Special cases (coincidence of the halfline with edges or vertices of the shape) are resolved by eliminating the coincidental elements and re-projecting the merged faces. The second algorithm, denoted 'the intersection method,' is applicable to any well- formed shape, including curved-surfaced ones. It reduces the dimensionality by intersecting the polygonal trace of the shape surface at the plane of intersection, which is tested for containing the trace of the point in the plane, directly establishing the overall 3D containment relationship. A particular O(n) implementation of the 2D point-in-polygon inclusion algorithm, which is used for solving the problem once reduced in dimensionality, is also presented. The presentation is complemented by discussions of the problems associated with point-polyhedron relationship determination in general, and comparative analysis of the two particular algorithms presented
keywords geometric modeling, point inclusion, polygons, polyhedra, computational geometry, algorithms, search, B-rep
series CADline
email kalay@socrates.berkeley.edu
last changed 2003/06/02 08:24

_id 2786
authors Woodwark, J.R.
year 1989
title Splitting Set-Theoretic Solid Models into Connected Components
source 10 p. : ill. Winchester: IBM UK Scientific Center, IBM United Kingdom Laboratories Limited, June, 1989. IBM UKSC 210. includes bibliography In general, there is no way to tell how many pieces (connected components) a set-theoretic (CSG) solid model represents, except via conversion to a boundary model. Recent work on the elimination of redundant primitives has been linked with techniques for identifying connected components in quad-trees and oct-trees into a strategy to attack this problem. Some success has been achieved, and an experimental Prolog program, working in two dimensions, that finds connected components and determines the set-theoretic representation of each component, is reported, and further developments proposed. CSG / quadtree / octree / primitives / algorithms. 43. Woodwark, J. R. and Quinlan K. M. 'Reducing the Effect of Complexity on Volume Model Evaluation.' Computer Aided Design. April, 1982. pp. 89-95 : ill. includes bibliography.
summary A major problem with volume modelling systems is that processing times may increase with model complexity in a worse than linear fashion. The authors have addressed this problem, for picture generation, by repeatedly dividing the space occupied by a model, and evaluating the sub-models created only when they meet a criterion of simplicity. Hidden surface elimination has been integrated with evaluation, in such a way that major portions of the model which are not visible are never evaluated. An example demonstrates a better than linear relationship between model complexity and computation time, and also shows the effect of picture complexity on the performance of the process
keywords CAD, computational geometry, solid modeling, geometric modeling, algorithms, hidden surfaces, CSG
series CADline
last changed 2003/06/02 11:58

_id c1bf
authors Gouraud, H.
year 1982
title Continuous shading of curved surfaces
source IEEE Transactions on Computers, 20, no. 6, 623-629
summary A procedure for computing shaded pictures of curved surfaces is presented. The surface is approximated by small polygons in order to solve easily the hidden-parts problem, but the shading of each polygon is computed so that the discontinuities of shade are eliminated across the surface and a smooth appearance is obtained. In order to achieve speed efficiency, the technique developed by Watkins is used which makes possible a hardware implementation of this algorithm.
series journal paper
last changed 2003/04/23 13:14

_id a426
authors Barsky, Brian A. and Greenberg, Donald P.
year 1982
title Interactive Surface Representation System Using a B-spline Formulation with Interpolation Capability
source computer Aided Design. July, 1982. vol. 14: pp. 187-194 : col.ill. includes bibliography
summary An interactive surface representation system is described which uses a parametric uniform bicubic B-spline formulation which can describe a surface initially defined to interpolate a specified network of points
keywords CAD, curved surfaces, computational geometry, interpolation, B-splines
series CADline
last changed 2003/06/02 11:58

_id 8a88
authors Anderson, David P.
year 1982
title Hidden Line Elimination in Projected Grid Surfaces
source ACM Transactions on Graphics. October, 1982. vol. 1: pp. 274-288 : ill. includes a short bibliography
summary The hidden line and hidden surface problems are simpler when restricted to special classes of objects. An example is the class of grid surfaces, that is, graphs of bivariate functions represented by their values on a set of grid points. Projected grid surfaces have geometric properties which permit hidden line or hidden surface elimination to be done more easily than in the general case. These properties are discussed in this paper, and an algorithm is given which exploits them
keywords algorithms, hidden lines, hidden surfaces, grids, computer graphics
series CADline
last changed 2003/06/02 08:24

_id 898a
authors Bay, J.H.
year 2002
title Cognitive Biases and Precedent Knowledge in Human and Computer-Aided Design Thinking
source CAADRIA 2002 [Proceedings of the 7th International Conference on Computer Aided Architectural Design Research in Asia / ISBN 983-2473-42-X] Cyberjaya (Malaysia) 18–20 April 2002, pp. 213-220
summary Cognitive biases (illusions) and potential errors can occur when using precedent knowledge for analogical, pre-parametric and qualitative design thinking. This paper refers largely to part of a completed research (Bay 2001) on how heuristic biases, discussed by Tversky and Kahneman (1982) in cognitive psychology, can affect judgement and learning of facts from precedents in architectural design, made explicit using a kernel of conceptual system (Tzonis et. al., 1978) and a framework of architectural representation (Tzonis 1992). These are used here to consider how such illusions and errors may be transferred to computer aided design thinking.
series CAADRIA
email akibayp@nus.edu.sg
last changed 2003/11/21 14:16

_id 1b10
id 1b10
authors Bay, Joo-Hwa
year 2001
title Cognitive Biases - The case of tropical architecture
source Delft University of Technology
summary This dissertation investigates, i) How cognitive biases (or illusions) may lead to errors in design thinking, ii) Why architects use architectural precedents as heuristics despite such possible errors, and iii) Develops a design tool that can overcome this type of errors through the introduction of a rebuttal mechanism. The mechanism controls biases and improves accuracy in architectural thinking. // The research method applied is interdisciplinary. It employs knowledge from cognitive science, environmental engineering, and architectural theory. The case study approach is also used. The investigation is made in the case of tropical architecture. The investigation of architectural biases draws from work by A. Tversky and D. Kahneman in 1982 on “Heuristics and biases”. According to Tversky and Kahneman, the use of heuristics of representativeness (based on similarity) and availability (based on ease of recall and imaginability) for judgement of probability can result in cognitive biases of illusions of validity and biases due to imaginability respectively. This theory can be used analogically to understand how errors arise in the judgement of environmental behaviour anticipated from various spatial configurations, leading to designs with dysfunctional performances when built. Incomplete information, limited time, and human mental resources make design thinking in practice difficult and impossible to solve. It is not possible to analyse all possible alternative solutions, multiple contingencies, and multiple conflicting demands, as doing so will lead to combinatorial explosion. One of the ways to cope with the difficult design problem is to use precedents as heuristic devices, as shortcuts in design thinking, and at the risk of errors. This is done with analogical, pre-parametric, and qualitative means of thinking, without quantitative calculations. Heuristics can be efficient and reasonably effective, but may not always be good enough or even correct, because they can have associated cognitive biases that lead to errors. Several debiasing strategies are discussed, and one possibility is to introduce a rebuttal mechanism to refocus the designer’s thinking on the negative and opposite outcomes in his judgements, in order to debias these illusions. The research is carried out within the framework of design theory developed by the Design Knowledge System Research Centre, TUDelft. This strategy is tested with an experiment. The results show that the introduction of a rebuttal mechanism can debias and improve design judgements substantially in environmental control. The tool developed has possible applications in design practice and education, and in particular, in the designing of sustainable environments.
keywords Design bias; Design knowledge; Design rebuttal; Design Precedent; Pre-parametric design; Tropical architecture; Sustainability
series thesis:PhD
type normal paper
email philipjhbay@gmail.com
last changed 2006/05/28 05:42

_id sigradi2006_e183a
id sigradi2006_e183a
authors Costa Couceiro, Mauro
year 2006
title La Arquitectura como Extensión Fenotípica Humana - Un Acercamiento Basado en Análisis Computacionales [Architecture as human phenotypic extension – An approach based on computational explorations]
source SIGraDi 2006 - [Proceedings of the 10th Iberoamerican Congress of Digital Graphics] Santiago de Chile - Chile 21-23 November 2006, pp. 56-60
summary The study describes some of the aspects tackled within a current Ph.D. research where architectural applications of constructive, structural and organization processes existing in biological systems are considered. The present information processing capacity of computers and the specific software development have allowed creating a bridge between two holistic nature disciplines: architecture and biology. The crossover between those disciplines entails a methodological paradigm change towards a new one based on the dynamical aspects of forms and compositions. Recent studies about artificial-natural intelligence (Hawkins, 2004) and developmental-evolutionary biology (Maturana, 2004) have added fundamental knowledge about the role of the analogy in the creative process and the relationship between forms and functions. The dimensions and restrictions of the Evo-Devo concepts are analyzed, developed and tested by software that combines parametric geometries, L-systems (Lindenmayer, 1990), shape-grammars (Stiny and Gips, 1971) and evolutionary algorithms (Holland, 1975) as a way of testing new architectural solutions within computable environments. It is pondered Lamarck´s (1744-1829) and Weismann (1834-1914) theoretical approaches to evolution where can be found significant opposing views. Lamarck´s theory assumes that an individual effort towards a specific evolutionary goal can cause change to descendents. On the other hand, Weismann defended that the germ cells are not affected by anything the body learns or any ability it acquires during its life, and cannot pass this information on to the next generation; this is called the Weismann barrier. Lamarck’s widely rejected theory has recently found a new place in artificial and natural intelligence researches as a valid explanation to some aspects of the human knowledge evolution phenomena, that is, the deliberate change of paradigms in the intentional research of solutions. As well as the analogy between genetics and architecture (Estévez and Shu, 2000) is useful in order to understand and program emergent complexity phenomena (Hopfield, 1982) for architectural solutions, also the consideration of architecture as a product of a human extended phenotype can help us to understand better its cultural dimension.
keywords evolutionary computation; genetic architectures; artificial/natural intelligence
series SIGRADI
email mail@maurocosta.com
last changed 2016/03/10 08:49

_id cf2011_p027
id cf2011_p027
authors Herssens, Jasmien; Heylighen Ann
year 2011
title A Framework of Haptic Design Parameters for Architects: Sensory Paradox Between Content and Representation
source Computer Aided Architectural Design Futures 2011 [Proceedings of the 14th International Conference on Computer Aided Architectural Design Futures / ISBN 9782874561429] Liege (Belgium) 4-8 July 2011, pp. 685-700.
summary Architects—like other designers—tend to think, know and work in a visual way. In design research, this way of knowing and working is highly valued as paramount to design expertise (Cross 1982, 2006). In case of architecture, however, it is not only a particular strength, but may as well be regarded as a serious weakness. The absence of non-visual features in traditional architectural spatial representations indicates how these are disregarded as important elements in conceiving space (Dischinger 2006). This bias towards vision, and the suppression of other senses—in the way architecture is conceived, taught and critiqued—results in a disappearance of sensory qualities (Pallasmaa 2005). Nevertheless, if architects design with more attention to non visual senses, they are able to contribute to more inclusive environments. Indeed if an environment offers a range of sensory triggers, people with different sensory capacities are able to navigate and enjoy it. Rather than implementing as many sensory triggers as possible, the intention is to make buildings and spaces accessible and enjoyable for more people, in line with the objective of inclusive design (Clarkson et al. 2007), also called Design for All or Universal Design (Ostroff 2001). Within this overall objective, the aim of our study is to develop haptic design parameters that support architects during design in paying more attention to the role of haptics, i.e. the sense of touch, in the built environment by informing them about the haptic implications of their design decisions. In the context of our study, haptic design parameters are defined as variables that can be decided upon by designers throughout the design process, and the value of which determines the haptic characteristics of the resulting design. These characteristics are based on the expertise of people who are congenitally blind, as they are more attentive to non visual information, and of professional caregivers working with them. The parameters do not intend to be prescriptive, nor to impose a particular method. Instead they seek to facilitate a more inclusive design attitude by informing designers and helping them to think differently. As the insights from the empirical studies with people born blind and caregivers have been reported elsewhere (Authors 2010), this paper starts by outlining the haptic design parameters resulting from them. Following the classification of haptics into active, dynamic and passive touch, the built environment unfolds into surfaces that can act as “movement”, “guiding” and/or “rest” plane. Furthermore design techniques are suggested to check the haptic qualities during the design process. Subsequently, the paper reports on a focus group interview/workshop with professional architects to assess the usability of the haptic design parameters for design practice. The architects were then asked to try out the parameters in the context of a concrete design project. The reactions suggest that the participating architects immediately picked up the underlying idea of the parameters, and recognized their relevance in relation to the design project at stake, but that their representation confronts us with a sensory paradox: although the parameters question the impact of the visual in architectural design, they are meant to be used by designers, who are used to think, know and work in a visual way.
keywords blindness, design parameters, haptics, inclusive design, vision
series CAAD Futures
email jherssens@gmail.com
last changed 2012/02/11 18:21

_id c7e9
authors Maver, T.W.
year 2002
title Predicting the Past, Remembering the Future
source SIGraDi 2002 - [Proceedings of the 6th Iberoamerican Congress of Digital Graphics] Caracas (Venezuela) 27-29 november 2002, pp. 2-3
summary Charlas Magistrales 2There never has been such an exciting moment in time in the extraordinary 30 year history of our subject area, as NOW,when the philosophical theoretical and practical issues of virtuality are taking centre stage.The PastThere have, of course, been other defining moments during these exciting 30 years:• the first algorithms for generating building layouts (circa 1965).• the first use of Computer graphics for building appraisal (circa 1966).• the first integrated package for building performance appraisal (circa 1972).• the first computer generated perspective drawings (circa 1973).• the first robust drafting systems (circa 1975).• the first dynamic energy models (circa 1982).• the first photorealistic colour imaging (circa 1986).• the first animations (circa 1988)• the first multimedia systems (circa 1995), and• the first convincing demonstrations of virtual reality (circa 1996).Whereas the CAAD community has been hugely inventive in the development of ICT applications to building design, it hasbeen woefully remiss in its attempts to evaluate the contribution of those developments to the quality of the built environmentor to the efficiency of the design process. In the absence of any real evidence, one can only conjecture regarding the realbenefits which fall, it is suggested, under the following headings:• Verisimilitude: The extraordinary quality of still and animated images of the formal qualities of the interiors and exteriorsof individual buildings and of whole neighborhoods must surely give great comfort to practitioners and their clients thatwhat is intended, formally, is what will be delivered, i.e. WYSIWYG - what you see is what you get.• Sustainability: The power of «first-principle» models of the dynamic energetic behaviour of buildings in response tochanging diurnal and seasonal conditions has the potential to save millions of dollars and dramatically to reduce thedamaging environmental pollution created by badly designed and managed buildings.• Productivity: CAD is now a multi-billion dollar business which offers design decision support systems which operate,effectively, across continents, time-zones, professions and companies.• Communication: Multi-media technology - cheap to deliver but high in value - is changing the way in which we canexplain and understand the past and, envisage and anticipate the future; virtual past and virtual future!MacromyopiaThe late John Lansdown offered the view, in his wonderfully prophetic way, that ...”the future will be just like the past, onlymore so...”So what can we expect the extraordinary trajectory of our subject area to be?To have any chance of being accurate we have to have an understanding of the phenomenon of macromyopia: thephenomenon exhibitted by society of greatly exaggerating the immediate short-term impact of new technologies (particularlythe information technologies) but, more importantly, seriously underestimating their sustained long-term impacts - socially,economically and intellectually . Examples of flawed predictions regarding the the future application of information technologiesinclude:• The British Government in 1880 declined to support the idea of a national telephonic system, backed by the argumentthat there were sufficient small boys in the countryside to run with messages.• Alexander Bell was modest enough to say that: «I am not boasting or exaggerating but I believe, one day, there will bea telephone in every American city».• Tom Watson, in 1943 said: «I think there is a world market for about 5 computers».• In 1977, Ken Olssop of Digital said: «There is no reason for any individuals to have a computer in their home».The FutureJust as the ascent of woman/man-kind can be attributed to her/his capacity to discover amplifiers of the modest humancapability, so we shall discover how best to exploit our most important amplifier - that of the intellect. The more we know themore we can figure; the more we can figure the more we understand; the more we understand the more we can appraise;the more we can appraise the more we can decide; the more we can decide the more we can act; the more we can act themore we can shape; and the more we can shape, the better the chance that we can leave for future generations a trulysustainable built environment which is fit-for-purpose, cost-beneficial, environmentally friendly and culturally significactCentral to this aspiration will be our understanding of the relationship between real and virtual worlds and how to moveeffortlessly between them. We need to be able to design, from within the virtual world, environments which may be real ormay remain virtual or, perhaps, be part real and part virtual.What is certain is that the next 30 years will be every bit as exciting and challenging as the first 30 years.
series SIGRADI
email t.w.maver@strath.ac.uk
last changed 2016/03/10 08:55

_id 941c
id 941c
authors Maver, T.W. and Ellis, J.
year 1982
title Implementation of an Energy Model within a Multi-Disciplinary Practice
source Proceedings of CAD82, Brighton (Ed: A Pipes), Butterworth, 562-570
summary Implementation of computer software is concerned with trials of its robustness, relevance, and efficacy in the real-world, real-time context of design practice. This paper summarises the trials carried out within the Building Design Partnership of a dynamic energy model, ESP, developed by ABACUS at the University of Strathclyde. Over an 18 month period the program was used on 6 projects to address a variety of design problems over a variety of building types. The paper reports in outline on each of the six: four concerned with the need for a definite answer to a specific question, eg. ''will it overheat in summer"; two concerned to provide, on the one hand for the client, on the other hand for the design practice, paradigms for energy conscious design of hospitals and offices. The conclusions drawn have relevance to the takeup of CAD generally.
series other
email t.w.maver@strath.ac.uk
last changed 2003/09/03 11:15

_id 2045
authors Balas, Egon
year 1982
title A Class of Location, Distribution and Scheduling Problems : Modeling and Solution Methods
source 21 p., 8 + 4 p. of appendix : ill. Carnegie Mellon University, Pittsburgh, PA: Design Research Center, December, 1982. includes bibliography
summary Discusses the potential of set covering techniques. Illustrates problem formulation techniques on several important classes of real-world problems. Also describes a class of algorithms for solving set covering problems, based on cutting planes, heuristics and subgradient optimization
keywords problem solving, methods, algorithms, problem definition, modeling, optimization, operations research
series CADline
last changed 1999/02/12 14:07

_id eabb
authors Boeykens, St. Geebelen, B. and Neuckermans, H.
year 2002
title Design phase transitions in object-oriented modeling of architecture
source Connecting the Real and the Virtual - design e-ducation [20th eCAADe Conference Proceedings / ISBN 0-9541183-0-8] Warsaw (Poland) 18-20 September 2002, pp. 310-313
summary The project IDEA+ aims to develop an “Integrated Design Environment for Architecture”. Its goal is providing a tool for the designer-architect that can be of assistance in the early-design phases. It should provide the possibility to perform tests (like heat or cost calculations) and simple simulations in the different (early) design phases, without the need for a fully detailed design or remodeling in a different application. The test for daylighting is already in development (Geebelen, to be published). The conceptual foundation for this design environment has been laid out in a scheme in which different design phases and scales are defined, together with appropriate tests at the different levels (Neuckermans, 1992). It is a translation of the “designerly” way of thinking of the architect (Cross, 1982). This conceptual model has been translated into a “Core Object Model” (Hendricx, 2000), which defines a structured object model to describe the necessary building model. These developments form the theoretical basis for the implementation of IDEA+ (both the data structure & prototype software), which is currently in progress. The research project addresses some issues, which are at the forefront of the architect’s interest while designing with CAAD. These are treated from the point of view of a practicing architect.
series eCAADe
email stefan.boeykens@asro.kuleuven.ac.be
last changed 2003/11/21 14:16

_id a747
authors Eastman, Charles M.
year 1982
title Recent Developments in Representation in the Science of Design
source 9 p. : ill. Pittsburgh: Design Research Center, CMU, April, 1982. includes bibliography
summary A recent goal in computer aided design is the representation of a design artifact in a form sufficient to support all analyses and to determine that the design is realizable. In this paper, the implications of the development of computer representations for design specifications are reviewed, some components of a theory of design representations are discussed, and the benefits of such a theory outlined
keywords CAD, theory, design, representation, architecture, geometric modeling
series CADline
email chuck.eastman@arch.gatech.edu
last changed 2003/05/17 08:15

_id cf2003_m_040
id cf2003_m_040
authors BAY, Joo-Hwa
year 2003
title Making Rebuttals Available Digitally for Minimising Biases in Mental Judgements
source Digital Design - Research and Practice [Proceedings of the 10th International Conference on Computer Aided Architectural Design Futures / ISBN 1-4020-1210-1] Tainan (Taiwan) 13–15 October 2003, pp. 147-156
summary The problem of heuristic biases (illusions) discussed by Tversky and Kahneman (1982) that can lead to errors in judgement by human designers, when they use precedent knowledge presented graphically (Bay 2001). A Cognitive framework of belief, goal, and decision, and a framework of representation of architectural knowledge by Tzonis are used to map out the problem of heuristic biases in the human mind. These are used to discuss what aspects of knowledge can be presented explicitly and digitally to users to make rebuttal more available for human thinking at the cognitive level. The discussion is applicable to both inductive and analytic digital knowledge systems that use precedent knowledge. This discussion is targeted directly at means of addressing bias in the human mind using digital means. The problem of human bias in machine learning and generalisation are discussed in a different paper, and the problems of international or non-intentional machine bias are not part of discussion in this paper.
keywords analogy, bias, design thinking, environmental design, heuristics
series CAAD Futures
last changed 2003/11/22 06:26

_id b47b
authors Callender, John Hancock (Ed.)
year 1982
title Time Saver Standards for Architectural Design Data
source McGraw Hill Book. Co., Sixth Ed.
summary From Book News, Inc. The latest version of the venerable reference first published in 1946 and most recently in 1982. Considers such aspects as bioclimate design, life-cycle costing, the building shell, architectural ethics, superstructure, acoustics, construction materials technology, daylighting, environmentally responsible design, and evaluating building performance. A special section features design data formatted according to the Uniformat II classification system, offering easy access to preliminary design and specification by building component, assemble, and place in the system of construction. Useful for any professional in the architecture, design, or construction fields. Book News, Inc.(r), Portland. Book Description Our biggest database of ready-to-use architectural design details ever. A classic reference for over 50 years. Time-Saver Standards for Architectural Design Data, edited by Donald Watson, Michael J. Crosbie, and John Hancock Callender, is the all-in-one desktop database that helps you work faster and smarter with instant design details-ready to incorporate into your architectural drawings the moment you need them. Now in a completely revised and updated seventh edition, this time-saving resource...
series other
last changed 2003/04/23 13:14

_id 66df
authors Cendes, Z.J., Minhas, F.U. and Silvester, P.P.
year 1982
title Universal Finite Element Matrices for Tetrahedra
source 45, [22] p Pittsburgh: Design Research Center, CMU, December, 1982. DRC- 18-58-82. includes bibliography.
summary Methods are described for forming finite element matrices for a wide variety of operators on tetrahedral finite elements, in a manner similar to that previously employed for line segments and triangles. This technique models the differentiation and product-embedding operators as rectangular matrices, and produces finite element matrices by replacing all required analytic operations by their finite matrix analogues. The method is illustrated by deriving the conventional matrix representation for Laplace's equation. Brief computer programs are given, which generate universal finite element matrices for use in various applications
keywords mathematics, computational geometry, finite elements, analysis
series CADline
last changed 2003/06/02 11:58

_id 89e4
authors Cendes, Z.J., Shenton, D. and H. Shahnasser
year 1982
title Adaptive Finite Element Mesh Generation Using the Delaunay Algorithm
source 3 p. : ill. Pittsburgh: Design Research Center, CMU, December, 1982
summary Includes bibliography. A two-dimensional generator is described which automatically creates optimal finite element meshes using the Delaunay triangulation algorithm. The mesh generator is adaptive in the sense that elements containing the largest normalized errors are automatically refined, providing meshes with a uniform error density. The system runs on a PERQ computer made by Three Rivers Computer Company. It is menu oriented and utilizes multiple command and display windows to create and edit the object description interactively. Mesh generation from the object data base is automatic, although it may be modified interactively by the user if desired. Application of the mesh generator to electric machine design and to magnetic bubble simulation shows it to be one of the most powerful and easy to use systems yet devised
keywords electrical engineering, triangulation, algorithms, OOPS, finite elements, analysis
series CADline
last changed 2003/06/02 11:58

_id adcd
authors Cohen, Paol R. and Feigenbaum, Edward A. (editors)
year 1982
title The Handbook of Artificial Intelligence
source xviii, 639 p. Stanford, California: HeurisTech Press, 1982. vol. 3: See The Handbook of Artificial intelligence edited by Avron, Barr and Feigenbaum, Edward. Includes bibliography p. 565-586 and cumulative indexes
summary Part of three volumes, this volume contains chapters on models of cognition, automatic deduction, vision, learning and planning
keywords AI, deduction, learning, cognition, planning
series CADline
last changed 2003/06/02 11:58

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